Finding the Fourth Proportional to 1,142.00, 1,576.06 and 644.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.00 : 1,576.06 = 644.76 : x
2. Step 2: Convert to fraction form
   1,142.00/1,576.06 = 644.76/x
3. Step 3: Cross multiply
   1,142.00x = 1,576.06 × 644.76
4. Step 4: Simplify right side
   1,142.00x = 1,016,178.83
5. Step 5: Solve for x
   x = 1,016,178.83/1,142.00
6. Step 6: Final answer
   x = 889.82